Vines twining, viscid, parasitic on various trees and shrubs by means of haustoria. Stem green or gray-brown, filiform, branched. Leaves reduced to minute scales. Flowers small, bisexual (plants rarely dioecious or nearly dioecious due to abortion), inserted in stalked or stalkless scalelike bracts, each with 2 bracteoles adnate to perianth base, all arranged into a spicate, capitate, or racemose inflorescence. Perianth tube turbinate or ovoid, contracted on top after anthesis; perianth lobes 6, in 2 series, outer 3 very small. Fertile stamens 9, rarely those of 2nd whorl reduced to narrow staminodes; filaments of 1st and 2nd whorls eglandular, those of 3rd whorl each with 2 subsessile glands; anthers 2-celled; cells of 1st and 2nd whorls introrse, those of 3rd whorl extrorse. Staminodes 3, of innermost whorl, stalkless or stalked. Ovary nearly not included in perianth tube when in flower, wholly included after anthesis due to dilated perianth tube contracted on top; style inconspicuous; stigma small or capitate, subsessile. Fruit included in dilated fleshy perianth tube, free; perianth tube with orifice and persistent lobes on top. Seeds thinly membranous or leathery; cotyledons fleshy, always unequal, ± hardened when mature, appressed, or separated when young but entirely connate when mature.

Between 15 and 20 species: tropical regions, with most species in Australia, a few in Africa, and one pantropical; one species in China.